Cable transmission is mainly based on the principle of total reflection of light.
Light is an electromagnetic wave. The wavelength range of visible light is 390~760nm. The part larger than 760nm is infrared light, the part smaller than 390nm is ultraviolet light, and the application of optical fiber is 850nm, 1300nm, 1310nm and 1550nm.
In the optical fiber communication system, the input signal sent to the optical transmitting end machine, the optical power outputted by the light source changes according to the magnitude of the input signal current, that is, the light source completes the electric/optical conversion, and the corresponding optical power signal is sent to the optical fiber for transmission; After the signal reaches the receiving end, the input optical signal is directly detected by the photodetector, and the optical/electrical conversion is completed. Then complete certain processing to restore it to the original electrical signal, thus completing the entire transmission process.
The manufacturing process of optical fiber is usually divided into two parts: the fabrication of optical fiber preform and the fiber drawing: the preparation process of optical fiber preform mainly includes four kinds of chemical vapor deposition (MCVD), axial vapor deposition (VAD), and external chemical vapor deposition. Method (OVD), plasma activated chemical vapor deposition (PCVD), our company’s optical fiber preform uses OVD+OVD process; fiber drawing is to clamp one end of the light bar in the drawing furnace, vertically, and the lower end is heated in the heating furnace. At about 2100 ° C, the ends are melted and then drawn into an optical fiber.
The optical fiber bare fiber is generally divided into three layers: a center high refractive index glass core, a low refractive index silicon glass cladding in the middle, and a reinforcing resin coating at the outermost. The fiber diameter is typically 245 μm (0.245 mm).
Post time: 2019-08-17